A cam phaser with a hydraulic valve is already known from DE 2006 012 733 B4 and DE 10 2006 012 755 B4. In this printed document cam switching moments are also described.
In order to provide high control quality also in combustion engines with highly variable cam switching torques DE 10 2010 014 500 provides that a shifting position of the hydraulic valve is proportionally controllable in which shifting position pressure spikes of the operating connection that is to be unloaded are blocked towards the supply connection and the operating connection to be loaded.
A hydraulic valve for a cam phaser is already known from EP 1 476 642 B1 wherein the hydraulic valve includes two hollow pistons which are supported at one another through a coil spring.
Thus, a gap between the two hollow pistons is openable and closeable.